@Pmk980 With possibly a little bit of work, you can get this truck to replace the sandking (or any other vehicle).
As a start, try comparing the sadler's (you want the first one)and the sandking (there are 2 versions of the sandking SANDKING is the 4 door one and, SANDKING2 is the 2 door one) meta lines in vehicles.meta [update\update.rpf\common
data\levels\gta5] and the handling.meta
[update\update.rpf\common\data]